Of course authoritarian governments routinely suppress critical voices using the courts. Who really finds justice in the legal system in a country run by a dictator, a theocracy, or a one party state? But, in the tense aftermath of the global financial crisis, the tactic of politically motivated prosecution is on the rise also in countries widely regarded as democratic.

Here’s an example. An economist publishes some macroeconomic analysis – relying entirely on publicly available information – that annoys a minister of finance. That minister encourages the securities regulator to investigate the author, supposedly for manipulation of the sovereign bond market – as if that market could be moved by any such opinion piece. The securities regulator refers the case to the public prosecutor, who takes evidence by interviewing a single “expert” – the minister of finance.

Authorities in other democracies – such as the UK or the US – cooperate fully with the country in question, despite the fact that the substantive claims are completely ridiculous and the legal process would be thrown out of any respectable court.

“One of the things I'm going to do if I win...I'm going to open up our libel laws so when they write purposely negative and horrible and false articles, we can sue them and win lots of money”

In a western European country there is eventual recourse through the courts. But the Portuguese system resembles the Court of Chancery in Bleak House. It is incredibly expensive to fight charges, and it takes years. Going all the way to the European Court of Human Rights, as sometimes proves necessary to secure justice, costs a small fortune.

The lesson is clear: do not annoy the Portuguese minister of finance, for example by juxtaposing his public statements with the actual facts.

“...thought up to silence voices that criticise the way the government is running the country and the consequences of the social, environmental and economic crises resulting from corruption, social cuts, undermined rights and the privatisation of public services."

There is no reason why this phenomenon will be limited to Europe. President Trump could easily arrange a criminal and regulatory investigation of this article, perhaps suggesting that the author was aiming to make a profit by affecting the price of US government debt or the value of one of his companies. Mr Trump is also explicit that he wants to be able to sue news organizations, so newspapers and other media should watch out.

Just because something is ridiculous, do not assume it will not happen in modern American politics. Pay attention to legal developments in Portugal and other European democracies. Powerful politicians are watching each other and developing shared strategies for suppressing informed debate across all forms of expression.

Mr Trump’s plans for the economy and national security deserve a great deal more scrutiny in the months ahead. But if he wins, it’s not clear that even emigration from the US would protect you from being pursued through the courts.

Simon Johnson is a professor at MIT’s Sloan School of Management and former chief economist of the IMF